ICD-10 code for minor chorea

The ICD-10-CM code for minor chorea is I02.9 (Rheumatic chorea without heart involvement). The official index lists 1 more specific code, so check the documentation for details such as type, cause, site or severity before settling on I02.9.

Within I02, choose I02.9 (without heart involvement) only when documentation doesn't support a more specific option: with heart involvement (I02.0).

As a secondary diagnosis it is a CC (complication or comorbidity), which can move an inpatient stay into the "with CC" MS-DRG of its family, unless the principal diagnosis excludes it.

In MS-DRG v44.0, it is part of the grouping logic for DRG 314 (Other Circulatory System Diagnoses with MCC, relative weight 2.0873), DRG 315 (Other Circulatory System Diagnoses with CC, relative weight 0.9508) and DRG 316 (Other Circulatory System Diagnoses without CC/MCC, relative weight 0.6677), in MDC 05 (Diseases and Disorders of the Circulatory System), as a principal or secondary diagnosis. The DRG a claim lands in depends on the principal diagnosis, procedures and any CC/MCC secondary diagnoses.